WO2017119561A1 - Method for controlling plurality of gateways in charge of user plane in gateway in charge of control plane - Google Patents

Abstract

Disclosed in the present specification is a method for controlling a plurality of gateways in charge of a user plane in a gateway in charge of a control plane. The method can comprise the steps of: receiving changed position information of a wireless device from an entity for managing the mobility of the wireless device; determining whether the gateway, for the user plane, suitable for the wireless device needs to be changed, on the basis of the position information and information on the characteristics of data delivered from the wireless device or to be delivered to the wireless device; transmitting a user plane creation request message to the gateway to be newly in charge of the user plane, when the change is needed; transmitting a user plane deletion request message to the gateway, which previously had been in charge of the user plane; and transmitting, to the entity, a notification message on whether the user plane has been changed.

Description

How to control multiple gateways that are responsible for the user plane from the gateway that is responsible for the control plane

The present disclosure relates to mobile communication.

In an effort to establish 3GPP (3 ^rd Generation Partnership Project) in optimizing the performance of 3GPP technologies from various forums and to respond to new technologies, the end of 2004 relating to the 4G mobile communication improved to the technical specifications of the mobile communications system As part of this, he started researching LTE / SAE (Long Term Evolution / System Architecture Evolution) technology.

The SAE, centered on 3GPP Service and System Aspects (WG2) working group 2 (WG2), determines the structure of the network in parallel with the LTE work of the 3GPP Technical Specification Group (TSG) radio access network (RAN), This is a study on network technology aimed at supporting the system and is one of the important standardization issues of 3GPP. This work aims to develop 3GPP system into a system supporting various wireless access technologies based on IP (internet protocol), and aims at optimized packet-based system that minimizes transmission delay with improved data transmission capability. Has been.

The Evolved Packet System (EPS) high-level reference model defined by 3GPP SA WG2 includes non-roaming cases and roaming cases in various scenarios. Reference may be made to Technical Specification (TS) 23.401 and TS 23.402. The network structure diagram of FIG. 1 is a simple reconfiguration.

1 illustrates an evolved mobile communication network It is a structure diagram .

An Evolved Packet Core (EPC) may include various components, and in FIG. 1, a part of the Evolved Packet Core (EPC) includes a Serving Gateway (S-GW) 52, a Packet Data Network Gateway (PW GW) 53, and an MME. (Mobility Management Entity) 51, Serving General Packet Radio Service (GPRS) Supporting Node (SGSN), and Enhanced Packet Data Gateway (ePDG) are shown.

The S-GW 52 acts as a boundary point between the radio access network (RAN) and the core network, and is an element that functions to maintain a data path between the eNodeB 22 and the PDN GW 53. In addition, when the UE (or user equipment: UE) moves over the area served by the eNodeB 22, the S-GW 52 serves as a local mobility anchor point. That is, packets may be routed through the S-GW 52 for mobility in the E-UTRAN (Universal Mobile Telecommunications System (Evolved-UMTS) Terrestrial Radio Access Network defined in 3GPP Release-8 or later). In addition, the S-GW 52 may be connected to other 3GPP networks (RANs defined before 3GPP Release-8, for example, UTRAN or GERAN (GSM (Global System for Mobile Communication) / EDGE (Enhanced Data rates for Global Evolution) Radio Access). It can also serve as an anchor point for mobility with a network).

PDN GW (or P-GW) 53 corresponds to the termination point of the data interface towards the packet data network. The PDN GW 53 may support policy enforcement features, packet filtering, charging support, and the like. In addition, for mobility management between 3GPP networks and non-3GPP networks (for example, untrusted networks such as Interworking Wireless Local Area Networks (I-WLANs), and trusted networks such as Code Division Multiple Access (CDMA) networks) Can serve as an anchor point.

Although the example of the network structure of FIG. 1 shows that the S-GW 52 and the PDN GW 53 are configured as separate gateways, two gateways may be implemented according to a single gateway configuration option. have.

The MME 51 is an element that performs signaling and control functions to support access to the network connection of the UE, allocation of network resources, tracking, paging, roaming and handover, and the like. . The MME 51 controls control plane functions related to subscriber and session management. The MME 51 manages a number of eNodeBs 22 and performs signaling for the selection of a conventional gateway for handover to other 2G / 3G networks. In addition, the MME 51 performs security procedures, terminal-to-network session handling, idle terminal location management, and the like.

The SGSN handles all packet data, such as user's mobility management and authentication to other connecting 3GPP networks (e.g., GPRS networks, UTRAN / GERAN).

The ePDG acts as a secure node for untrusted non-3GPP networks (eg, I-WLAN, WiFi hotspots, etc.).

As described with reference to FIG. 1, a terminal (or UE) having IP capability is provided by an operator (ie, an operator) via various elements in the EPC, based on 3GPP access as well as non-3GPP access. Access to an IP service network (eg, IMS).

1 illustrates various reference points (eg, S1-U, S1-MME, etc.). In the 3GPP system, a conceptual link defining two functions existing in different functional entities of E-UTRAN and EPC is defined as a reference point. Table 1 below summarizes the reference points shown in FIG. 1. In addition to the examples of Table 1, there may be various reference points according to the network structure.

Reference point	Explanation
S1-MME	Reference point for control plane protocol between E-UTRAN and MME
S1-U	Reference point between E-UTRAN and SGW for inter-eNB eNB switching and per-bearer user plane tunneling during handover
S3	Reference point between MME and SGSN that provides user and bearer information exchange for mobility between 3GPP access networks in idle and / or active state. This reference point can be used in PLMN-to-PLMN-to-for example (for PLMN-to-PLMN handover))
S4	Reference point between SGW and SGSN that provides relevant control and mobility support between the GPRS core and SGW's 3GPP anchor functionality. It also provides user plane tunneling if no direct tunnel is established.
S5	Reference point providing user plane tunneling and tunnel management between the SGW and PDN GW. Used for SGW relocation because of UE mobility and when a connection to the PDN GW where the SGW is not co-located is required for the required PDN connectivity.
S11	Reference point between MME and SGW
SGi	Reference point between the PDN GW and the PDN. The PDN may be an operator external public or private PDN or, for example, an in-operator PDN for the provision of IMS services. This reference point corresponds to Gi of 3GPP access

2 is generally E- With UTRAN  Represent the functions of the main nodes of a typical EPC It is an illustration .

As shown, the eNodeB 20 is responsible for routing to the gateway, scheduling and sending paging messages, scheduling and sending broadcast channels (BCHs), and uplink and downlink resources while the RRC connection is active. Function for dynamic allocation, configuration and provision for measurement of the eNodeB 20, radio bearer control, radio admission control, and connection mobility control. Within the EPC, paging can occur, LTE_IDLE state management, user planes can perform encryption, EPS bearer control, NAS signaling encryption and integrity protection.

Degree 3 is UE and eNodeB  The structure of the Radio Interface Protocol in the control plane between Illustrative 4 shows another structure of a radio interface protocol in a user plane between a terminal and a base station. It is an illustration .

The radio interface protocol is based on the 3GPP radio access network standard. The air interface protocol is composed of a physical layer, a data link layer, and a network layer horizontally, and a user plane and control for data information transmission vertically. It is divided into a control plane for signal transmission.

The protocol layers are based on the lower three layers of the Open System Interconnection (OSI) reference model, which is well known in communication systems, and includes L1 (first layer), L2 (second layer), and L3 (third layer). ) Can be separated.

Hereinafter, each layer of the radio protocol of the control plane shown in FIG. 3 and the radio protocol in the user plane shown in FIG. 4 will be described.

The physical layer, which is the first layer, provides an information transfer service using a physical channel. The physical layer is connected to a medium access control layer on the upper side through a transport channel, and data between the medium access control layer and the physical layer is transmitted through the transport channel. In addition, data is transferred between different physical layers, that is, between physical layers of a transmitting side and a receiving side through a physical channel.

The physical channel is composed of several subframes on the time axis and several sub-carriers on the frequency axis. Here, one subframe includes a plurality of symbols and a plurality of subcarriers on the time axis. One subframe consists of a plurality of resource blocks, and one resource block consists of a plurality of symbols and a plurality of subcarriers. The transmission time interval (TTI), which is a unit time for transmitting data, is 1 ms corresponding to one subframe.

According to 3GPP LTE, the physical channels existing in the physical layer of the transmitting side and the receiving side are physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH) and physical downlink control channel (PDCCH), which are control channels, It may be divided into a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid-ARQ Indicator Channel (PHICH), and a Physical Uplink Control Channel (PUCCH).

The PCFICH transmitted in the first OFDM symbol of a subframe carries a control format indicator (CFI) regarding the number of OFDM symbols (that is, the size of the control region) used for transmission of control channels in the subframe. The wireless device first receives the CFI on the PCFICH and then monitors the PDCCH.

Unlike the PDCCH, the PCFICH does not use blind decoding and is transmitted on a fixed PCFICH resource of a subframe.

The PHICH carries a positive-acknowledgement (ACK) / negative-acknowledgement (NACK) signal for a UL hybrid automatic repeat request (HARQ). The ACK / NACK signal for uplink (UL) data on the PUSCH transmitted by the wireless device is transmitted on the PHICH.

The Physical Broadcast Channel (PBCH) is transmitted in the preceding four OFDM symbols of the second slot of the first subframe of the radio frame. The PBCH carries system information necessary for the wireless device to communicate with the base station, and the system information transmitted through the PBCH is called a master information block (MIB). In comparison, system information transmitted on the PDSCH indicated by the PDCCH is called a system information block (SIB).

The PDCCH includes resource allocation and transmission format of downlink-shared channel (DL-SCH), resource allocation information of uplink shared channel (UL-SCH), paging information on PCH, system information on DL-SCH, and random access transmitted on PDSCH. Resource allocation of higher layer control messages such as responses, sets of transmit power control commands for individual UEs in any UE group, activation of voice over internet protocol (VoIP), and the like. A plurality of PDCCHs may be transmitted in the control region, and the terminal may monitor the plurality of PDCCHs. The PDCCH is transmitted on an aggregation of one or several consecutive control channel elements (CCEs). CCE is a logical allocation unit used to provide a PDCCH with a coding rate according to a state of a radio channel. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH and the number of bits of the PDCCH are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs.

Control information transmitted through the PDCCH is called downlink control information (DCI). DCI is a resource allocation of PDSCH (also called DL grant), a PUSCH resource allocation (also called UL grant), a set of transmit power control commands for individual UEs in any UE group. And / or activation of Voice over Internet Protocol (VoIP).

There are several layers in the second layer. First, the Medium Access Control (MAC) layer is responsible for mapping various logical channels to various transport channels, and also for multiplexing logical channel multiplexing to map multiple logical channels to one transport channel. Play a role. The MAC layer is connected to the RLC layer, which is the upper layer, by a logical channel. The logical channel includes a control channel for transmitting information of a control plane according to the type of information to be transmitted. It is divided into a traffic channel that transmits user plane information.

The Radio Link Control (RLC) layer of the second layer adjusts the data size so that the lower layer is suitable for transmitting data to the radio section by segmenting and concatenating data received from the upper layer. It plays a role. In addition, in order to guarantee various QoS required by each radio bearer (RB), TM (Transparent Mode), UM (Un-acknowledged Mode), and AM (Acknowledged Mode, Response mode). In particular, the AM RLC performs a retransmission function through an automatic repeat and request (ARQ) function for reliable data transmission.

The Packet Data Convergence Protocol (PDCP) layer of the second layer is an IP containing relatively large and unnecessary control information for efficient transmission in a wireless bandwidth where bandwidth is small when transmitting an IP packet such as IPv4 or IPv6. Performs Header Compression which reduces the packet header size. This transmits only the necessary information in the header portion of the data, thereby increasing the transmission efficiency of the radio section. In addition, in the LTE system, the PDCP layer also performs a security function, which is composed of encryption (Ciphering) to prevent third-party data interception and integrity protection (Integrity protection) to prevent third-party data manipulation.

The radio resource control layer (hereinafter RRC) layer located at the top of the third layer is defined only in the control plane, and the configuration and resetting of radio bearers (abbreviated as RBs) are performed. It is responsible for the control of logical channels, transport channels and physical channels in relation to configuration and release. In this case, RB means a service provided by the second layer for data transmission between the terminal and the E-UTRAN.

When there is an RRC connection (RRC connection) between the RRC of the terminal and the RRC layer of the wireless network, the terminal is in the RRC connected mode (Connected Mode), otherwise it is in the RRC idle mode (Idle Mode).

Hereinafter, the RRC state and the RRC connection method of the UE will be described. The RRC state refers to whether or not the RRC of the UE is in a logical connection with the RRC of the E-UTRAN. If the RRC state is connected, the RRC_CONNECTED state is called, and the RRC_IDLE state is not connected. Since the UE in the RRC_CONNECTED state has an RRC connection, the E-UTRAN can grasp the existence of the UE in units of cells, and thus can effectively control the UE. On the other hand, the UE in the RRC_IDLE state cannot identify the existence of the UE by the E-UTRAN, and the core network manages the unit in a larger tracking area (TA) unit than the cell. That is, the terminal in the RRC_IDLE state is only detected whether the terminal exists in a larger area than the cell, and the terminal must transition to the RRC_CONNECTED state in order to receive a normal mobile communication service such as voice or data. Each TA is identified by a tracking area identity (TAI). The terminal may configure a TAI through a tracking area code (TAC), which is information broadcast in a cell.

When the user first turns on the power of the terminal, the terminal first searches for an appropriate cell, then establishes an RRC connection in the cell, and registers the terminal's information in the core network. Thereafter, the terminal stays in the RRC_IDLE state. The terminal staying in the RRC_IDLE state (re) selects a cell as needed and looks at system information or paging information. This is called camping on the cell. When it is necessary to establish an RRC connection, the UE staying in the RRC_IDLE state makes an RRC connection with the RRC of the E-UTRAN through an RRC connection procedure and transitions to the RRC_CONNECTED state. There are several cases in which the UE in RRC_IDLE state needs to establish an RRC connection. For example, when an uplink data transmission is necessary due to a user's call attempt, or when a paging message is received from E-UTRAN, Send a response message.

A non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.

The following describes the NAS layer shown in FIG. 3 in detail.

Evolved Session Management (ESM) belonging to the NAS layer performs functions such as default bearer management and dedicated bearer management, and is responsible for controlling the terminal to use the PS service from the network. The basic bearer resource is characterized in that it is allocated from the network when the network is first connected to a specific PDN (Packet Data Network). In this case, the network allocates an IP address usable by the terminal so that the terminal can use the data service, and also allocates a quality of service (QoS) of the basic bearer. LTE supports two types of bearer having a guaranteed bandwidth rate (GBR) QoS characteristic that guarantees a specific bandwidth for data transmission and reception, and a non-GBR bearer having a best effort QoS characteristic without guaranteeing bandwidth. do. In case of a basic bearer, a non-GBR-bearer is allocated. In the case of a dedicated bearer, a bearer having a QoS characteristic of GBR or non-GBR may be allocated.

The bearer allocated to the UE in the network is called an evolved packet service (EPS) bearer, and when the EPS bearer is allocated, the network allocates one ID. This is called EPS bearer ID. One EPS bearer has QoS characteristics of a maximum bit rate (MBR), a guaranteed bit rate (GBR), or an aggregated maximum bit rate (AMBR).

5A is 3GPP In LTE  A flowchart illustrating a random access process.

The random access procedure is used for the UE 10 to obtain UL synchronization or to allocate UL radio resources to the base station, that is, the eNodeB 20.

The UE 10 receives a root index and a physical random access channel (PRACH) configuration index from the eNodeB 20. Each cell has 64 candidate random access preambles defined by a Zadoff-Chu (ZC) sequence, and the root index is a logical index for the UE to generate 64 candidate random access preambles.

Transmission of the random access preamble is limited to a specific time and frequency resource for each cell. The PRACH configuration index indicates a specific subframe and a preamble format capable of transmitting the random access preamble.

UE 10 transmits a randomly selected random access preamble to eNodeB 20. The UE 10 selects one of the 64 candidate random access preambles. Then, the corresponding subframe is selected by the PRACH configuration index. UE 10 transmits the selected random access preamble in the selected subframe.

Upon receiving the random access preamble, the eNodeB 20 sends a random access response (RAR) to the UE 10. The random access response is detected in two steps. First, the UE 10 detects a PDCCH masked with a random access-RNTI (RA-RNTI). The UE 10 receives a random access response in a medium access control (MAC) protocol data unit (PDU) on the PDSCH indicated by the detected PDCCH.

5b illustrates a connection process in a radio resource control (RRC) layer.

As shown in FIG. 5B, an RRC state is shown depending on whether RRC is connected. The RRC state refers to whether or not an entity of the RRC layer of the UE 10 is in a logical connection with an entity of the RRC layer of the eNodeB 20. If the RRC state is connected, the RRC state is connected. A state that is not connected is called an RRC idle state.

Since the UE 10 in the connected state has an RRC connection, the E-UTRAN may determine the existence of the corresponding UE in units of cells, and thus may effectively control the UE 10. On the other hand, the UE 10 in the idle state cannot be understood by the eNodeB 20, and is managed by a core network in units of a tracking area, which is a larger area than a cell. The tracking area is a collection unit of cells. That is, the idle state UE (10) is identified only in the presence of a large area unit, in order to receive the normal mobile communication services such as voice or data, the terminal must transition to the connected state (connected state).

When the user first powers up the UE 10, the UE 10 first searches for a suitable cell and then remains in an idle state in that cell. When the UE 10 staying in the idle state needs to establish an RRC connection, the UE 10 establishes an RRC connection with the RRC layer of the eNodeB 20 through an RRC connection procedure and performs an RRC connection state ( connected state).

There are several cases in which the UE in the idle state needs to establish an RRC connection. For example, a user's call attempt or an uplink data transmission is necessary, or a paging message is received from EUTRAN. In this case, the response message may be transmitted.

In order to establish an RRC connection with the eNodeB 20, the UE 10 in an idle state must proceed with an RRC connection procedure as described above. The RRC connection process is largely a process in which the UE 10 sends an RRC connection request message to the eNodeB 20, and the eNodeB 20 transmits an RRC connection setup message to the UE 10. And a process in which the UE 10 sends an RRC connection setup complete message to the eNodeB 20. This process will be described in more detail with reference to FIG. 4B.

1) When the UE 10 in idle state attempts to establish an RRC connection due to a call attempt, a data transmission attempt, or a response to the paging of the eNodeB 20, the UE 10 first performs an RRC connection. A RRC connection request message is transmitted to the eNodeB 20.

2) When the RRC connection request message is received from the UE 10, the eNB 10 accepts the RRC connection request of the UE 10 when the radio resources are sufficient, and establishes an RRC connection that is a response message (RRC connection). setup) message is transmitted to the UE 10.

3) When the UE 10 receives the RRC connection setup message, the UE 10 transmits an RRC connection setup complete message to the eNodeB 20. When the UE 10 successfully transmits an RRC connection establishment message, the UE 10 establishes an RRC connection with the eNodeB 20 and transitions to the RRC connected mode.

FIG. 6 is S- shown in FIG. GW , P- GW  Interface, etc.

Referring to FIG. 6, an interface between an S-GW, a P-GW, a traffic detection function (TDF), and an operator's IP service network is shown.

S1-U is an interface for data transmission between the S-GW user plane and the E-UTRAN. S5 / 8-U is an interface for data transmission between the S-GW user plane and the P-GW user plane. SGi is an interface for data transfer between the P-GW user plane and the TDF user plane. S11 is an interface for transmission of control signals between the S-GW control plane and the MME. S5 / 8-C is an interface for the transmission of control signals between the S-GW control plane and the P-GW control plane.

The dotted line in the illustrated interface represents the interface of the control plane, and the solid line represents the interface of the user plane. Here, it can be seen that both the S-GW and the P-GW process the control plane and the user plane.

However, considering that a higher speed data service is required in the next generation mobile communication, so-called fifth generation mobile communication, it may not be efficient for the S-GW and the P-GW to cover both the control plane and the user plane.

Therefore, one disclosure of the present specification is intended to propose a solution that can solve the above problems.

In order to achieve the above object, one disclosure of the present specification discloses an S-GW CP (or S-GW-C) and a user plane (UP) in charge of the control plane (CP). S-GW UP (or S-GW-U) is suggested. Through such separation, a plurality of S-GW UPs may be disposed in a geographically closer location to the UE, and managed through one S-GW CP.

However, according to the existing procedure, since the S-GW CP may not obtain the latest location information of the UE from the MME, it may not be able to determine which S-GW UP is suitable for the UE.

Accordingly, to further solve this problem, one disclosure of the present specification proposes to transmit information related to a UE to the S-GW CP when the MME receives a service request message from an idle UE.

In addition, another disclosure of the present specification proposes an operation method of the S-GW CP when the information related to the UE is thus obtained from the MME as follows.

According to the disclosure of the present specification, it is possible to solve the problems of the prior art.

1 is a structural diagram of an evolved mobile communication network.

Figure 2 is an exemplary view showing the architecture of a general E-UTRAN and a general EPC.

3 is an exemplary diagram illustrating a structure of a radio interface protocol in a control plane between a UE and an eNodeB.

4 is another exemplary diagram illustrating a structure of a radio interface protocol in a user plane between a terminal and a base station.

5a is a flowchart illustrating a random access procedure in 3GPP LTE.

5b illustrates a connection process in a radio resource control (RRC) layer.

FIG. 6 illustrates an interface of S-GW, P-GW, and the like shown in FIG. 1.

7 shows an example of dividing the S-GW, P-GW and TDF into a user plane and a control plane for next generation mobile communication.

8 shows an example in which the S-GW CP shown in FIG. 7 is responsible for a plurality of S-GW UPs.

9 shows coverage of each S-GW UP when the S-GW CP is in charge of a plurality of S-GW UPs.

FIG. 10 illustrates a process in which a UE in idle state performs a service request procedure to start uplink data transmission.

FIG. 11 is an exemplary diagram illustrating a method according to the present disclosure in a situation of performing a service request procedure for uplink data transmission of a UE.

12 is an exemplary diagram illustrating a method according to the present disclosure in a situation where a UE performs a service request procedure for reception of downlink data.

13 is a configuration block diagram of a UE 100 and an S-GW CP according to an embodiment of the present invention.

Although the present invention is described based on the Universal Mobile Telecommunication System (UMTS) and the Evolved Packet Core (EPC), the present invention is not limited to such a communication system, but also to all communication systems and methods to which the technical spirit of the present invention can be applied. Can be applied.

It is to be noted that the technical terms used herein are merely used to describe particular embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined in this specification, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately represent the spirit of the present invention, it should be replaced with technical terms that can be understood correctly by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.

Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “having” should not be construed as necessarily including all of the various components, or various steps described in the specification, and some of the components or some of the steps are included. It should be construed that it may not be, or may further include additional components or steps.

In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but other components may be present in between. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and should not be construed as limiting the spirit of the present invention by the accompanying drawings. The spirit of the present invention should be construed to extend to all changes, equivalents, and substitutes in addition to the accompanying drawings.

In the accompanying drawings, although a user equipment (UE) is illustrated as an example, the illustrated UE may be referred to in terms of terminal, mobile equipment (ME), and the like. In addition, the UE may be a portable device such as a laptop, a mobile phone, a PDA, a smart phone, a multimedia device, or a non-portable device such as a PC or a vehicle-mounted device.

Definition of Terms

Before describing with reference to the drawings, in order to help the understanding of the present invention, terms used herein will be briefly defined.

GERAN: An acronym for GSM EDGE Radio Access Network, and refers to a wireless access section connecting a core network and a terminal by GSM / EDGE.

UTRAN: Abbreviation for Universal Terrestrial Radio Access Network, and refers to a wireless access section connecting a terminal and a core network of 3G mobile communication.

E-UTRAN: Abbreviation for Evolved Universal Terrestrial Radio Access Network, and refers to a 4G mobile communication, that is, a wireless access section connecting a terminal to a LTE core network.

UMTS: stands for Universal Mobile Telecommunication System and means a core network of 3G mobile communication.

UE / MS: means User Equipment / Mobile Station, terminal equipment.

EPS: stands for Evolved Packet System and means a core network supporting a Long Term Evolution (LTE) network. UMTS evolved network

Public Data Network (PDN): An independent network on which servers providing services are located

PDN connection: connection from the terminal to the PDN, that is, association (connection) between the terminal represented by the IP address and the PDN represented by the APN

PDN-GW (Packet Data Network Gateway): Network node of EPS network that performs UE IP address allocation, Packet screening & filtering, Charging data collection

Serving GW (Serving Gateway): Network node of EPS network performing Mobility anchor, Packet routing, Idle mode packet buffering, Triggering MME to page UE

PCRF (Policy and Charging Rule Function): Node of EPS network that performs policy decision to apply differentiated QoS and charging policy dynamically according to service flow

APN (Access Point Name): A name of an access point managed in a network, which is provided to a UE. That is, a string that refers to or distinguishes a PDN. In order to connect to the requested service or network (PDN), the P-GW goes through the name. A predefined name (string) in the network to find this P-GW (example) internet.mnc012.mcc345.gprs

Tunnel Endpoint Identifier (TEID): End point ID of a tunnel established between nodes in a network, and is set for each section in bearer units of each UE.

NodeB: A base station of a UMTS network, which is installed outdoors, and a cell coverage scale corresponds to a macro cell.

eNodeB: A base station of an evolved packet system (EPS), which is installed outdoors, and a cell coverage size corresponds to a macro cell.

(e) NodeB: A term referring to NodeB and eNodeB.

MME, which stands for Mobility Management Entity, serves to control each entity in EPS to provide session and mobility for the UE.

Session: A session is a channel for data transmission. The unit may be a PDN, a bearer, or an IP flow unit. The difference in each unit can be divided into the entire target network unit (APN or PDN unit), the QoS classification unit (Bearer unit), and the destination IP address unit as defined in 3GPP.

PDN connection (connection): A connection from the terminal to the PDN, that is, the association (connection) between the terminal represented by the IP address and the PDN represented by the APN. This means an inter-entity connection (terminal-PDN GW) in the core network so that a session can be established.

UE Context: Context information of UE used to manage UE in the network, ie Context Information composed of UE id, mobility (current location, etc.), session attributes (QoS, priority, etc.)

NAS (Non-Access-Stratum): Upper stratum of a control plane between a UE and an MME. Support mobility management, session management, IP address maintenance between UE and network

RAT: Abbreviation for Radio Access Technology, which means GERAN, UTRAN, E-UTRAN and the like.

CUPS: Abbreviation for Control and User Plane Separation. In the 3GPP network nodes (e.g., S-GW, P-GW, TDF), the control plane (hereinafter referred to as CP) and the user plane (UP) are called UP. Means to separate). The control plane controls one or a plurality of user planes arranged geographically and flexibly.

On the other hand, the embodiments presented below may be implemented alone, but may be implemented in a combination of several embodiments.

7 is S- for the next generation mobile communication. GW , P- GW  And TDF  An example of dividing into a user plane and a control plane is shown.

As described above, the next-generation mobile communication requires high-speed data service, and as shown in FIG. 7, the functions of the S-GW, P-GW, and TDF may be separated into a user plane and a control plane. Is required. This separation can be called Control and User Plane Separation (CUPS).

As shown, the S-GW is an S-GW CP (or S-GW-C) that is in charge of the Control Plane (CP) and an S-GW UP (or is in charge of the User Plane (UP)). S-GW-U). In addition, the P-GW may be divided into a P-GW CP (or P-GW-C) that is responsible for the control plane and a P-GW UP (or P-GW-U) that is responsible for the user plane. Similarly, the TDF may be divided into a TDF CP (or TDF-C) that is in charge of the control plane and a TDF UP (or TDF-U) that is in charge of the user plane.

Sxa shown here is an interface for transmission of control signals between the S-GW CP and the S-GW UP. Sxb is an interface for transmitting a control signal between the P-GW CP and the P-GW UP. Similarly, Sxc is an interface for transmission of control signals between TDF CP and TDF UP.

However, this separated network structure should satisfy the following requirements.

-Interwork with existing network In addition, separate network functions must be linked to other non-separated network functions.

It should not affect the UE and Radio Access Network (RAN).

There should be no need to define new interfaces with other network nodes other than S-GW, P-GW and TDF.

-S-GW / P-GW selection function of MME / ePDG / TWAN should be used as it is.

The existing configuration based on the mechanism for the selection of the control plane functional entities of the TDF shall be available.

Support one or more control plane functional entities in connection with one or more user plane functional entities.

FIG. 8 is S- shown in FIG. GW  CP is a plurality of S- GW  The example in charge of UP is shown.

As shown in FIG. 8, the S-GW CP may be in charge of a plurality of S-GW UPs, thereby enabling dynamic optimization of the user plane. That is, the S-GW CP may select an optimal S-GW UP in consideration of a load state, a geographic location, and the like.

For the selection of the UP, the parameters to be considered by the CP and the time of triggering the selection will be described as follows.

(a) Parameters to be considered by the CP for the selection of UP

i. UE location

The location of the UE may be considered to select a UP that is close to the location of the UE. The granularity of the location may be an E-UTRAN Cell Global ID (ECGI) or a Tracking Area Identity (TAI). If the position of the UE is considered for the selection of the user plane, the position of the UE may also be considered for the selection of the control plane.

ii. Capability of user plane and function or feature required for the UE

An appropriate user plane may be selected that meets the necessary functionality for the UE. The function required for the UE may be inferred from information such as APN, UE usage type, etc., or may be derived from PCRF. The ability of the entity responsible for the user plane may be set in the control plane or negotiated during the initial connection establishment procedure between the control plane and the user plane.

In addition to the above two, the control plane may further obtain and consider current load state information of the user plane.

(b) When to trigger the selection of UP

i. Establish a PDN Connection

At the time of PDN connection establishment (including E-UTRAN attach procedure) a new user plane needs to be selected.

ii. X2 / S1-based Handover Procedure

If X2 / S1 based handover occurs, the user plane closer to the location of the UE needs to be selected.

iii. Service Request Process

When the UE performs a service request procedure, a user plane closer to the location of the UE needs to be selected.

iv. Load balancing

For the purpose of load balancing, a new user plane needs to be selected.

9 is S- GW  CP is a plurality of S- GW  When in charge of UP, each S- GW  UP's Coverage  Indicates.

The existing S-GW was in charge of a wide range of coverage including several tracking areas (TAs). Referring to FIG. 9, the S-GW UP may be in charge of only a reduced coverage area. Here, the coverage of the S-GW UP may be classified in units of TAs. For example, the coverage of S-GW UP 1 may include TA 1, TA 2, TA 3, and the coverage of S-GW UP 2 may include TA 4, TA 5, and TA 6.

As such, the S-GW UP is responsible for only a smaller coverage area than the existing S-GW, thereby allowing the UE to receive better quality of service (eg, reduced delay due to fewer UEs).

To this end, the S-GW CP must manage the coverage area and real-time load information of each S-GW UP and all control information related to EPS bearer setup provided by each S-GW UP.

The S-GW CP should be able to select an appropriate S-GW UP based on the network topology, the location of the UE, and the service area.

However, how the S-GW CP can obtain the latest location information of the UE from the MME has not been defined previously. Specifically, since the MME has information on the coverage area of the S-GW in the form of a list of TAIs, there is no detailed information on the coverage area for each S-GW UP. Even if the MME has information about coverage of each S-GW UP, it does not know whether real-time load or service is available. Therefore, when the UE moves to the TA unit, the MME does not provide the S-GW CP with information on whether the current S-GW UP is optimal. For example, the service request procedure will be described with reference to FIG. 10 as follows.

10 is in an idle state UE  A process of performing a service request procedure to start uplink data transmission is shown.

1) If there is uplink data to be transmitted by the UE in the idle state, the service request procedure starts. That is, the UE 100 transmits a NAS layer based service request message to the eNodeB 200.

2) The eNodeB 200 includes the service request message in an S1 message called an initial UE message and transmits it to the MME 510. In this case, the eNodeB 200 transmits the ID (ie, TAI) and ECGI of the tracking area TA where the UE 100 is located to the MME 510.

3) An authentication / security procedure is performed between the UE 100, the MME 510, and the Home Subscriber Server (HSS) 540.

4) The MME 510 transmits an initial context setup request message to the eNodeB 200 in an S1-AP (Application Protocol) message.

5) The eNodeB 200 establishes a radio bearer with the UE 100.

6) Then, the UE 100 may transmit uplink data.

7) Meanwhile, the eNodeB 200 includes an initial context setup complete message in the S1-AP message and transmits it.

8) The MME 510 transmits a bearer modification request message to the S-GW 520.

9) The S-GW 520 sends a bearer modification request message to the P-GW 530.

10) The P-GW 530 modifies an IP connectivity access network (IP-CAN) session with the PCRF 550.

11) The P-GW 530 transmits a Bearer Modify Response (Modify Bearer Response) message to the S-GW 520.

12) The S-GW 520 transmits the bearer modification response message to the MME 510.

The MME 510 receiving the service request message in step 2) processes the S-GW address and S1-TEID (s) that the UE has serviced before moving to the idle state, whether or not the UE moves in the process 4). Send to eNodeB 200. This causes the UE 100 to have a data path that may not be optimal.

In step 8), the MME 510 simply transmits only a bearer modification request message to the S-GW 520 and delivers location information (ie, TAI and ECGI) of the UE to the S-GW 520. I never do that. Specifically, the MME 510 includes the location information of the UE in the bearer request message only when the P-GW / PCRF requests the location information change report of the UE 100 and generally does not include the location information of the UE. Does not simply send a bearer request message.

Accordingly, if the existing service request procedure shown in FIG. 10 is used as it is, the S-GW CP cannot obtain the location information of the UE from the MME 510. GW UP cannot be selected.

On the other hand, after the data path is created according to the completion of the process shown in 12), if the S-GW CP is able to know the location information of the UE as a ratio, a situation that may need to change the data path during data transmission and reception may occur. have. However, if the data path is changed during data transmission / reception, network load and data transmission / reception delay may occur.

Therefore, a solution for this will be described below.

<Solution according to the disclosure of the present specification>

The disclosure of the present specification suggests the following solution. At this time, the disclosure of the present specification assumes that the S-GW CP and the S-GW UP are separated from each other. Assume that one S-GW CP controls a plurality of S-GW UPs.

When the MME receives the service request message from the UE in the idle state, it transmits the following information related to the UE to the S-GW CP.

i) current location information of the UE (e.g., TA ID or ECGI)

ii) Type of service the UE wishes to receive (information included in the subscription information of the UE, obtained directly from the UE, or inferred / processed as a combination of the information)

iii) Whether downlink data to be delivered to the UE is in the S-GW (when a Downlink Data Notification (DDN) message is received from the S-GW CP). This information may be known to the S-GW CP in advance.

iv) characteristics of uplink data that the UE intends to transmit or characteristics of data buffered in the S-GW UP (the characteristics of data buffered in the S-GW UP may be known in advance by the S-GW CP). For example, data that can be delivered in one or a few transactions in small data, relatively large data such as OS upgrades, or operator's preset and provisioning mechanisms such as real-time voice services. Mechanisms that can be used to identify and distinguish between the network and the UE.

The above information is used when the S-GW CP selects an optimal S-GW UP for the UE. That is, the S-GW CP can select which S-GW UP is most optimal for the UE and whether the S-GW UP should be changed immediately or after the data transmission is completed.

Based on the information received from the MME, the S-GW CP performs one of the following operations.

A. Immediately change the existing S-GW UP to the optimal S-GW UP.

B. Send data without changing existing S-GW UP immediately. The S-GW CP may start the S-GW UP change timer for later S-GW UP change.

At this time, when the S-GW CP selects the optimal S-GW UP for the UE, the TA ID or ECGI of the UE, subscription information, characteristics of uplink data that the UE intends to transmit, or S-GW UP presented in the above section Consider the characteristics of the data buffered in the, the load status information of each S-GW UP.

Conditions for the S-GW CP to perform the above A or B is as follows.

First, the condition that the S-GW CP performs the A is when one of the following is satisfied.

A-1. The UE has sent a service request message to receive the downlink data (ie, response to paging) and the guard timer for buffering the downlink data has not expired.

Specifically, when the S-GW CP is determined based on the subscriber information of the UE received from the MME and the characteristic information of the downlink data buffered in the S-GW UP, the downlink data is delayed tolerant or If the data is likely to be subsequently transmitted (eg, large file transfer), the S-GW CP performs the A.

A-2. When the UE transmits a service request message for transmission of uplink data.

Specifically, when the S-GW CP determines based on the subscription information (or may be delivered by the UE) received from the MME and the characteristics of the service requested by the UE, the service requested by the UE is irrelevant to the delay. If it is determined that a delay tolerant service or a service having a high probability of subsequent data transmission occurs, the S-GW CP performs the A.

A-3. After the CP of the S-GW delays the change of the S-GW UP according to B, i) the change timer for the UE has expired, or ii) the load of the existing S-GW UP has exceeded the threshold, or iii) When a mobility related procedure (eg, X2-based handover) occurs, the S-GW CP performs the A operation.

Next, the condition under which the S-GW CP performs the B operation is when one of the following is satisfied.

B-1. If the load of the S-GW UP that the S-GW CP chooses to be the best for the UE is overloaded than the existing S-GW UP or has a load above the threshold.

B-2a. When the UE transmits a service request message for receiving downlink data (response to paging), and a protection timer regarding buffering of downlink data has not expired.

Specifically, when the S-GW CP is determined based on the subscription information of the UE received from the MME and the characteristic information of the downlink data buffered in the S-GW UP, the downlink data is delay sensitive or If it is determined that subsequent data transmission is unlikely to occur, the S-GW CP performs the B operation.

B-2b. When the UE transmits a service request message due to uplink data

Specifically, the S-GW CP analyzes the subscription information (or may be delivered by the UE) and characteristics of the service requested by the UE received from the MME, so that the service requested by the UE is delay-sensitive or subsequent data transmission. If it is determined that the service is unlikely to occur, the S-GW CP performs the B operation.

B-2c. After the CP of the S-GW delays the change of the S-GW UP, i) the change timer for the UE has expired, ii) the load of the existing S-GW UP has exceeded the threshold, or iii) the UE's mobility-related procedure ( For example, when X2-based handover occurs, the S-GW CP checks the load of the S-GW UP serving the UE and performs the B operation.

11 is Of UE  In the context of performing a service request procedure for uplink data transmission, a method according to the present disclosure is shown. It is an illustration .

1) If there is uplink data to be transmitted by the UE in the idle state, the service request procedure starts. That is, the UE 100 transmits a NAS layer based service request message to the eNodeB 200. In this case, the UE 100 includes information on a type of service or a feature of the service that it needs in the service request message.

2) The eNodeB 200 includes the service request message in an S1 message called an initial UE message and transmits it to the MME 510. At this time, the eNodeB 200 transmits the ID (ie TAI) and ECGI of the tracking area where the UE 100 is located to the MME 510.

3) An authentication / security procedure is performed between the UE 100 and the MME 510 and the HSS 540.

4) The MME 510 transmits a UE information change message including the changed location information of the UE to the S-GW CP 520a. In this case, the message may include information about the type of service or the feature of the service that the UE 100 requires. Alternatively, the message may include information on characteristics of uplink data that the UE intends to transmit.

5) Then, the S-GW CP 520a determines whether to change the S-GW UP based on the information obtained from the MME 510. Specifically, S-GW CP (520a) is based on the current position information of the UE, information on the characteristics of the uplink data to be transmitted by the UE, information on the characteristics of the service requested by the UE, the optimal S- Select GW UP. If the selected S-GW UP is different from before, it is determined whether to change the S-GW UP immediately or later. If it is determined that the S-GW UP 1 520b should be changed immediately from the S-GW UP 2 520c for the UE, the S-GW CP 520a performs the following steps 6) to 9). do. However, if it is decided not to change, the following processes 6) to 9) are not performed.

6) The S-GW CP 520a transmits a Create UP Request message to the changed S-GW UP 2 520c. In this case, the S-GW CP 520a includes information (eg, MME TEID, UE context, etc.) related to the UE PDN connection that it has in the user plane generation message.

7) The S-GW UP 2 520c allocates a resource for the UE based on the information received from the S-GW CP 520a and controls related information (eg, TEID) in a control plane creation response (Create CP Response). The message is included in the message and transmitted to the S-GW CP 520a.

8) The S-GW CP 520c transmits a user plane delete request message to the S-GW UP 1 520b which previously served the UE.

9) The S-GW UP 1 520b releases the resources allocated for the UE and transmits a user plane delete response message to the S-GW CP 520.

10) The S-GW CP 520a transmits a user plane change notification message to the MME 510 including its decision and related information. If the S-GW UP 1 is changed from the S-GW UP 1 to the S-GW UP 2, the S-GW CP 520a includes information indicating this in the message. However, if the S-GW UP has not changed, the S-GW CP 520a includes information indicating this in the message.

11) The MME 510 transmits an initial context setup request message to the eNodeB 200 in an S1-AP message. In this case, information about the S-GW UP 2 is included in the initial context setup request message.

12) The eNodeB 200 establishes a radio bearer with the UE 100.

Meanwhile, the user plane is thus set up, thereby creating an uplink data path.

13) Meanwhile, the eNodeB 200 includes an initial context setup complete message in the S1-AP message and transmits it.

14) The MME 510 transmits a bearer modification request message to the S-GW CP 520a.

If there is a change in S-GW UP above, the S-GW CP 520 transmits a bearer modification request message to the new S-GW UP 2 520c. At this time, the bearer modification request message transmitted to the new S-GW UP 2 520c includes the address of the eNodeB, S1 TEID. In addition, the DL packet delay notification request is included.

The S-GW CP 520 receives a bearer modification response message from the new S-GW UP 2 520c.

17-18) If there was no change of S-GW UP from above, instead of steps 15) and 16), the S-GW CP 520 transmits a bearer modification request message to S-GW UP 1 520b. Receive a bearer modification response message.

19-20) The S-GW CP 520a transmits a bearer modification request message to the P-GW 530. If the S-GW UP 1 is changed from the S-GW UP 1 to the S-GW UP 2, the S-GW CP 520a includes information indicating this in the message. However, if the S-GW UP has not changed, the S-GW CP 520a includes information indicating this in the message.

21) The S-GW CP 520a transmits the bearer modification response message to the MME 510.

12 is UE  In the context of performing a service request procedure for receiving downlink data, a method according to the present disclosure is shown. It is an illustration .

0) When the P-GW 530 receives the downlink data to be delivered to the UE 100, the P-GW 530 transmits the downlink data to the S-GW UP 1 520b that is in charge of the user plane of the UE 100. The P-GW 530 transmits a downlink data notification (DDN) message indicating that the S-GW UP 1 520b has the downlink data to the S-GW CP 520a. Alternatively, when the S-GW UP 1 520b receives downlink data from the P-GW 530, the S-GW UP 1 520b transmits a DDN message indicating that the S-GW UP 1 520b has downlink data to the S-GW CP 520. do. In this case, the DDN message may include information on the characteristics of the downlink data. The S-GW CP 520a delivers the DDN to the MME 510. The MME 510 transmits a paging signal to the eNodeB 200, and the eNodeB 200 broadcasts the paging signal.

1) When the UE in the idle state receives the paging message, the service request procedure is started to receive the downlink data. That is, the UE 100 transmits a NAS layer based service request message to the eNodeB 200.

Processes 2) to 3) are the same as processes 2) to 3) of FIG. 11.

4) The MME 510 transmits a UE information change message including the changed location information of the UE to the S-GW CP 520a.

5) Then, the S-GW CP 520a determines whether to change the S-GW UP based on the information obtained from the information obtained from the MME 510. In detail, the S-GW CP 520a selects an optimal S-GW UP based on current location information of the UE and information on characteristics of downlink data to be transmitted to the UE. If the selected S-GW UP is different from before, it is determined whether to change the S-GW UP immediately or later.

6) to 7) process is the same as the process 6) to 7) of FIG.

8) The S-GW CP 520a transmits an Update S-GW UP Request message of the S-GW UP to the P-GW 530, whereby the P-GW transmits the S-GW of the UE. Update information on the UP (eg, S-GW UP TEID, etc.).

9) The P-GW 530 transmits an Update S-GW UP Response to the S-GW CP 520a.

10) The S-GW CP 520a transmits a user plane change notification message to the MME 510 including its decision and related information. If the S-GW UP 1 is changed from the S-GW UP 1 to the S-GW UP 2, the S-GW CP 520a includes information indicating this in the message. However, if the S-GW UP has not changed, the S-GW CP 520a includes information indicating this in the message.

11) The S-GW CP 520c transmits a user plane delete request message to the S-GW UP 1 520b which previously served the UE.

12) The S-GW UP 1 520b transmits the buffered data to the S-GW UP 2 520c.

13) After the transmission of the buffered data is completed, the S-GW UP 1 520b releases the resources allocated for the UE, and sends a user plane delete response message to the S-GW CP (S-GW CP). 520).

14) to 15) process is the same as the process 11) to 12) of FIG.

In this way, the user plane is set up, thereby creating a downlink data path.

16) to 24) process is the same as the process 13) to 21) of FIG.

The contents described so far can be implemented in hardware. This will be described with reference to FIG. 14.

13 shows the present invention Example  According UE 100 and S- GW  Composition of CP Block diagram .

As shown in FIG. 13, the UE 100 includes a storage means 101, a processor 102, and a transceiver 103. The S-GW CP 520a includes a storage means 521, a processor 522, and a transceiver 523.

The storage means store the method described above.

The controllers control the storage means and the transceiver. Specifically, the controllers each execute the methods stored in the storage means. The controllers transmit the aforementioned signals through the transceivers.

In the above description of the preferred embodiments of the present invention by way of example, the scope of the present invention is not limited only to these specific embodiments, the present invention is in various forms within the scope of the spirit and claims of the present invention Can be modified, changed, or improved.

Claims (14)

1. As a method for controlling a plurality of gateways in charge of a user plane from a gateway in charge of a control plane (Control Plane),

   Receiving changed location information of the wireless device from an entity managing the mobility of the wireless device;

   Determining whether a gateway of a user plane suitable for the wireless device is required based on the location information and information on characteristics of data to be transmitted from or transmitted to the wireless device;

   If the change is necessary, transmitting a request message for creating a user plane to a gateway that will be in charge of a new user plane;

   Transmitting a delete request message of the user plane to a gateway previously in charge of the user plane;

   Sending a notification message as to whether the user plane has changed.
2. The method of claim 1, wherein the changed location information of the wireless device is

   And received via a user information change message.
3. The method of claim 2, wherein the user information change message is

   Information about characteristics of data transmitted from the wireless device;

   And at least one of information on a characteristic of a service requested by the wireless device.
4. The method of claim 1, wherein determining whether the change is necessary comprises:

   Determining whether the change is necessary;

   If the change is necessary, determining whether the change should be performed immediately.
5. The method of claim 4, wherein

   The creation request message of the user plane and the delete request message of the user plane are transmitted when it is determined that the change should be performed immediately.
6. The method of claim 1,

   Receiving a notification message indicating that a gateway previously responsible for the user plane has data to forward to the wireless device.
7. 7. The method of claim 6, wherein the notification message includes information about characteristics of data to be delivered to the wireless device.
8. The method of claim 6, wherein the deletion request message of the user plane

   And instructing the gateway that was previously in charge of the user plane to transfer data to be delivered to the wireless device to the gateway to be newly in charge.
9. As a gateway that controls a plurality of gateways in charge of a user plane, and controls a control plane (Control Plane),

   A receiving unit which receives changed location information of the wireless device from an entity managing mobility of the wireless device;

   A processor for determining whether a gateway of a user plane suitable for the wireless device is required based on the location information and information on characteristics of data to be transmitted from or to the wireless device;

   If the change is necessary, the user plane creation request message is transmitted to the gateway that will newly handle the user plane, the delete request message of the user plane is transmitted to the gateway that was previously in charge of the user plane, and the user plane is changed to the entity. Gateway comprising a transmitting unit for transmitting a notification message on whether or not.
10. The method of claim 9, wherein the changed location information of the wireless device is

    The gateway characterized in that it is received via a user information change message.
11. The method of claim 10, wherein the user information change message is

    Information about characteristics of data transmitted from the wireless device;

    And at least one of information on a characteristic of a service requested by the wireless device.
12. The method of claim 9, wherein the receiving unit

    And further receive a notification message indicating that the gateway previously in charge of the user plane has data to forward to the wireless device.
13. The gateway of claim 12, wherein the notification message includes information on a characteristic of data to be transmitted to the wireless device.
14. The method of claim 12, wherein the delete request message of the user plane

    And the gateway in charge of the user plane instructs the wireless device to transfer data to be delivered to the wireless device to the gateway to be newly in charge.

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